Sewing machine attachment for aligning a reinforcement member in a hem

ABSTRACT

A hem folding attachment for folding a reinforcement member into the end of a strip of material prior to insertion of the folded end of the strip of material into a hem forming maching. The attachment including a frame or table having a guide mounted on the frame for aligning the strip of material on the table and a hem stop mounted on the frame for engaging the end of the strip of material. The reinforcement member is aligned on the top of the strip of material in a spaced relation to the hem stop. A folder bar is mounted on the frame beneath the strip of material for movement upwardly into engagement with the strip of material to fold the end of the strip of material around the reinforcement member. A shuttle is moved into engagement with the reinforcement member and folds the end of the strip over the top of the reinforcement member. The shuttle includes a clamp for engaging the reinforcement member prior to the movement of the shuttle transversely to feed the strip into the hem forming machine.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an automatic sewing machine attachmentfor positioning a hanger strip or weight in the hem of a vertical blindprior to stitching.

2. Description of the Prior Art

At the present time, fabric type vertical blinds are hemmed manuallyTypically, the hem is formed by hot melt glue, sonic welding, heatsealing, as well as sewing. Sonic welding or sewing are fairlysophisticated systems however, the steps of folding, loading, insertingor unloading of the hem in the vertical blind are still manuallyperformed This can be time consuming and costly due to operator errorresulting in rejection of the finished product.

The sewing process has been automated to the extent of providing aloading station for the vertical blind once the hem is folded which thenautomatically feeds the hem into the sewing head and the hem ejectedupon completion. If a hanger is to be included in the top hem or aweight in the bottom hem, it must be inserted by hand by the operatorprior to placing the hem in the loading station for the sewing machine.The edges of the hem must be closed by stitches or glue in order toretain the hanger or weight in the hem. Speed of operation, therefore,is dependent upon the dexterity of a particular operator.

SUMMARY OF THE PRESENT INVENTION

The present invention is directed to improvements in the technique forplacing a hanger strip or weight in the hem of a vertical blind prior tothe sewing operation. In general, in accordance with the presentinvention, once the strips for the vertical blind are cut to size andpresented to the loading station, the hanger strips or weights areautomatically positioned on the strip, the strip is folded to form thehem and the strip fed into the sewing machine to stitch the hem.

The hanger is retained in the hem by the interengagement of the hangerwith the folded edge of the hem. The weight is retained in the bottomhem by the hem stitching.

One of the advantages of the present invention is the increasedproduction capability as well as the increase in accuracy in thealignment of the hangers or weights in the hem.

Another advantage of the present invention is the elimination of theextra steps required.

Other objects and advantages of the invention will become apparent fromthe following detailed description when read in connection with theaccompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the general arrangement of the loadingstation with respect to the hanger magazine and the sewing machine.

FIG. 2 is a side elevation view of the loading station.

FIG. 3 is a top plan view of the loading station with the top plateremoved.

FIG. 4 is a side elevation view of a portion of the loading stationshowing the folder bar in the up position.

FIG. 5 is a side elevation view of a portion of the loading stationshowing the folder bar in the down position and the shuttle in a clampposition.

FIG. 6 is a view of the clamp shuttle with the wiper plate in the foldposition.

FIG. 7 is a side elevational view of a portion of the loading stationshowing the shuttle in the transverse position with the hold bar in thedown position.

FIG. 8 is a plan view of a portion of the loading station showing thestrip moved transversely into the sewing machine.

FIG. 9. is a front elevation view in section of the magazine.

FIG. 9A is a plan view of the transfer blade with a hanger position inthe blade.

FIG. 10 is a side elevation view of the magazine in section showing themagazine discharge assembly.

FIGS. 11 through 19 are schematic views of the sequence of operation ofthe loading apparatus.

FIG. 20 is a perspective view of a portion of the end of the strip witha hanger aligned with the slot hemming the strip.

FIG. 21 is a perspective view of the hem with the hanger locked in thehem.

FIG. 22 is a perspective view of a bottom hem.

Before describing one embodiment of the invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction or the arrangement of components set forth inthe following description and illustrated in the drawings. The inventionis capable of other embodiments and can be practiced or carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein is for the purpose of description and shouldnot be regarded as limiting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The loading attachment 10, according to the present invention, is usedto automatically form a hem at each end of a strip 12 of material for avertical blind. The hem 11 at the top of the strip of material includinga reinforcemennt member in the form of a hanger 14. The hem 13 at thebottom of the strip of material may also include a reinforcement memberin the form of a weight 195. The strip 12 is transferred to a sewingmachine 16 wherein the folded end 15 is stitched to the strip ofmaterial to join the hem. The sewing machine 16 is of a conventionaldesign and includes a presser foot 18 for holding the folded end as thestrip passes the needle 20. Although a sewing machine is describedherein, the attachment 10 can be used in combination with other hemforming machines such as hot melt glue, sonic welding or heat sealing.

Referring to FIGS. 20 and 21, the end 15 of a a strip 12 of verticalmaterial is shown having a slot 22 near the end of the blind. A tophanger 14 having a tab 24 is placed on the end of the strip 12 with thetab 24 aligned with the slot 22. The end 15 of the strip 12 is foldedover to the position shown in FIG. 21 with the tab 24 projecting throughthe opening 22. As seen in FIG. 21, the hem is formed by the stitching26 which is sewn across the folded end 15 of the strip 12. The tab 24cooperates with the slot 22 to prevent the top hanger 14 from slidingout of the pocket formed in the end of the vertical blind as moreparticularly described hereinafter. In FIG. 22, a wide hem 13 is shownat the bottom of the strip 12 with the weight 195 having a tab 197 onone side that can be sewn into the bottom hem.

The attachment 10 generally includes a frame 26 having a plate 28mounted thereon to form a table located in a coplanar relation with thetable top 30 for the sewing machine 16. The top hangers 14 are stored onthe plate 28 by means of a magazine 32. In this regard, the magazine 32includes a base 34, a pair of end walls 36, and a pair of side walls 38.The top hangers 14 are aligned in the magazine by means of a adjustablewall 40 which is supported on end wall 36 by rods 42. The top hangers 14are supported in the magazine on a base plate 44. The side walls 38 arespaced upwardly from the base plate 44 a distance corresponding to thethickness of the top hangers 14 thereby forming a slot 46 for dischargeof the hanger strips from the magazine.

Means are provided for discharging the hanger strips from the magazine.Such means is in the form of a pusher plate 48 which is aligned with theslots 46 of the magazine. The plate 48 is mounted on a block 50 that issecured to the end of a piston 52 of a pneumatic piston and cylinderassembly 54. The cylinder 56 of the piston and cylinder assembly 54 ismounted on a cross block 58 which is supported on the magazine by plates60. The top hangers 14 are biased to the bottom of the magazine by meansof a weight block 62.

Means are provided for moving the hangers 14 from the magazine 32 to aposition in alignment with the end of the strip 12. Such means is in theform of a blade 64 having ribs 66 along each edge of the blade 64 and anotch 70 at the end of blade 64. The hanger strips 14 are dischargedfrom the magazine into the top of the blade 64 with the tab 24 alignedin a notch 68 in the rib 66. The rib 66 is tapered on one side of thenotch 68 to allow the tab 24 to clear the notch 68 when the blade ispulled out of the hem. Means are provided for moving the blade acrossthe plate 28. Such means is in the form of a block 61 which is mountedon a rod 63 supported at one end by a fixed plate 65 and at the otherend by a plate 67 mounted on end wall 36. The block 61 is reciprocatedon the rod 63 by a rocker arm 69 having a slot 73 at one end and anopening 75 at the other end. The rocker arm 69 is mounted for pivotalmovement on a pin 71 which is mounted on plate 38 and aligned with slot73. Bearing plates 65 are provided on pin 71 on each side of arm 69. Theother end of the rocker arm 69 is connected to the block 61 by means ofa pin 77 which is mounted on block 61 and aligned in opening 75.

The rocker arm 69 is reciprocated around pin 71 by means of a pneumaticpiston and cylinder assembly 79 which includes a piston 81 and acylinder 83. The cylinder 83 is mounted in a cylinder block 85 that ispivotally connected to the rocker arm by a pin 87. The piston 81 isconnected to a pin 89 secured to the end wall 36.

The blade 64 is clamped into position on top of the end of the strip 12by means of a clamp assembly 91 which engages the notch 70 by blade 64.In this regard, the clamp 91 includes a pneumatic piston and cylinderassembly 93 having a cylinder 95 mounted on a frame member 97 and apiston 99 having a cap 101 mounted on the end. The piston is alignedwith slot 70 in the end of blade 64.

The strip 12 is aligned on the plate 28 by means of a guide 72 with theend of the strip engagement with a hem stop 74. The guide 72 is mountedfor vertical motion on bracket 76. The guide is provided with a slot 78at each end and is supported on the brackets 76 by means of pins 80which are aligned with slots 78. The guide 72 is moved vertically bymeans of pneumatic piston and cylinder assembly 73 connected to theguide 72 and to a cross frame member 76A that is secured to brackets 76.The upward movement of the guide plate 72 is limited by means of pins 84which engage the lower end of the slot 78 when the guide plate is movedupward.

The hem stop bar 74 includes a cross block 86 which is moved up and downby means of a pneumatic piston and cylinder assembly 90 having a piston88 and a cylinder 92. The cross block 86 is mounted on the end of piston88. The cylinder 92 is supported in a slide block 94 for horizontalmovement to adjust the length of the hem on the vertical blind 12 asdescribed hereinafter.

The end 15 of the strip 12 is folded around the blade 64 by means of afolder plate 100, as seen in FIG. 4. The folder plate 100 is moved upand down by means of a pneumatic piston and cylinder assembly 104 havinga piston 102 and cylinder 106. The cylinder 106 is secured to frame 108and the piston 102 is connected to the folder plate 100. The hem stop 74and folder plate 100 are withdrawn to a position below the plate 28 toallow the shuttle 110 (FIG. 5) to move in a position to engage the oneend of the strip 12 folded around hanger 14.

In this regard, the shuttle 110 includes a backing plate 112 which issupported on a pair of rods 114. The rods 114 are mounted for transversemovement with respect to the plate 28 by means of a fixed block 116. Thebacking plate 112 and rods 114 are moved transversely with respect tothe fixed block 116 by means of a piston and cylinder assembly 118having a cylinder 120 and a piston 124. The cylinder 120 is secured to amounting block 122 on the back of the fixed block 116. The piston 124 isconnected to a block 126 secured to the plate 112. With this arrangementthe shuttle 110 can be moved from the position shown in FIG. 3 which isin alignment with the end of the strip 12 to the position shown in FIG.8 with the strip 12 aligned with the sewing machine 16.

The folded end of the strip 12 is clamped in the shuttle 110 between aclamping plate 128 and a support plate 142. The clamping plate 128 ispivotally mounted on the backing plate 112 by means of pins 130. Thesupport plate 142 is mounted on the backing plate 112. The clampingplate 128 is pivoted by means of a pair of pneumatic piston and cylinderassemblies 132 having cylinders 134 and pistons 136. The cylinders 134are pivotally mounted on the upper end of the backing plate 112 by pins137 and the pistons 136 are pivotally connected to the clamping plate128 by pins 140.

The shuttle 110 is moved into engagement with the hem of the strip 12 bymeans of a piston and cylinder assembly 144 mounted on a cross plate 146in the frame 26. The piston 148 of the piston and cylinder assembly 144is connected to the slide block 150 which is secured to the block 116.The slide block 150 is mounted for horizontal motion on rods 152 thatare secured to the main frame 26.

Means are provided on the clamp plate 128 for folding the end 15 of thestrip 12 over the blade 64. Such means is in the form of a wiper plate141 as seen in FIG. 5. The wiper plate 141 is supported on the clampplate 128 by means of a piston and cylinder assembly 145 having a piston143 and a cylinder 147. The cylinder 147 is mounted on the top of clampplate 128 and the piston 143 is connected to the wiper plate 141.

Means are also provided on the clamp plate 128 for engaging the edge ofthe end 15 of the strip 12 when the clamp plate 128 is closed. Suchmeans is in the form of a saw blade 129 mounted on the face of plate128. The saw teeth will be embedded into the strip of material.

When the shuttle 110 is moved toward the sewing machine 16, the end 15of the strip 12 moves under a hold down bar 154 which is mounted on theend of an arm 156 mounted on the sewing machine 16 and is aligned withthe presser foot 18. The hold down bar 154 is moved downward to engagethe end of the hem 15 by means of a piston and cylinder assembly 160.

Means are provided for moving the folding end of the strip 12 under thehold down bar 154. Such means is in the form of an air dischargeassembly 162 mounted on the plate 128. The assembly 162 includes a block164 having an outlet 166 which is directed downwardly toward the edge ofthe end of the strip. As the shuttle is moved toward the hold down bar154, a blast of air is directed toward the the strip 12 to force the enddownward under the hold down plate 154.

The forming of the hem as described above refers to the upper or top hem11 of the vertical blind. If the loading attachment 10 is to be used forforming a hem at the lower end of the strip 12 for a weight 195, asshown in FIG. 22, the hem stop 86 and shuttle 110 are moved away fromthe folder bar 100 in order to increase the width of the hem 13. Theweight 195 is provided with a tab 197 that is stitched into the hem whenthe strip is fed to the sewing machine. The adjustment of the hem stop86 and shuttle 110 is made by means of a hem adjust piston and cylinderassembly 180 having a cylinder 182 and a piston 184. The cylinder 182 ismounted on a cross bar 186 on frame 26. The end of piston 182 is securedto a stop block 188 that is guided by rod 190 for horizontal motion withrespect to cross bar 186. The piston 148, as noted above, is connectedto slide block 150.

As shown in FIGS. 2 and 3, the slide block 150 includes a plate 190 thatdepends vertically into the path of stop block 188. It should be notedthat when piston 184 is drawn into cylinder 183 as shown in phantom inFIG. 2, the stop block 188 and hem stop 86 will also move with the endof piston 184. The shuttle cylinder 144 which is actuated at the sametime moves the slide block 150 toward the cylinder 144 until the plate190 engages the member 188. The shuttle 110, which is carried by theslide block 150, will move with slide block 150 to increase the width ofthe hem. The width of the hem can be adjusted by means of a thumb screw200 mounted on pin 96 to more accurately adjust the width of the hem.

Sequence of Operation

The sequence of operation of the attachment 10 is shown in FIGS. 11through 19. The steps of the sequence are as follows:

Step 1 (FIG. 11), a vertical blind strip 12 is positioned against theguide 72 in abutting relation to the hem stop 74.

Step 2 (FIG. 12), the blade 64 has been moved away from the magazine tocarry a hanger 14 to a position where tab 24 is aligned with slot 22 instrip 12.

Step 3 (FIG. 13), the hold down clamp 91 is aligned with the slot 70 onthe end of the blade 64.

Step 4 (FIG. 14), the clamp 91 is moved downward to hold the blade 64against the strip 12; and the hem stop guide 74 is moved downward belowshuttle 110 and the folder plate 100 is moved upward to fold the end 15vertically with respect to the blade 64.

Step 5 (FIG. 15), folder plate 100 is moved downward and the shuttle 110is moved toward the folded end of strip 12 to fold end 15 over the topof the hanger 14. The clamp 91 is released from the end of the blade 64and the hanger blade 64 is pulled out of the hem. The hanger 14 isretained in the hem by the engagement of tab 24 with slot 22.

Step 6 (FIG. 16), the clamp 128 on the shuttle 110 is closed to hold theend 15 against the hanger 14.

Step 7 (FIG. 17), the guide 72 is moved downward and the shuttle 110 isretracted to pull the strip 12 and into alignment with the hold downplate 154.

Step 8 (FIG. 18), the shuttle 110 is moved transversely to move thefolded end of the strip 12 under the plate 154. At the same time, airfrom the air assembly 162 may directed against the end 15 to force theedge of the end 15 under the hold down bar 54. The shuttle is movedtransversely far enough to move the folded end under the presser feet 18of the sewing machine which then automatically feeds the strip throughthe sewing machine to stitch the hem. It should be noted that the hanger14 is retained in the hem by means of the engagement of tab 24 with theslot 22.

Step 9 (FIG. 19), as the strip is moved transversely into the sewingmachine 16, the guide 72 is moved to its upper position and the hemguide 74 is moved into position to receive the next strip 12 ofmaterial. As the guide 72 is moved upward, the shuttle is returned toits initial position. The strip 12 can then be inserted into theassembly as shown in FIG. 11 to repeat the sequence of operation.

Thus, it is apparent that there has been provided, in accordance withthe invention, a sewing machine attachment that fully satisfies the aimsand advantages set forth above. When the invention has been described inconjunction with specific embodiments thereof, it is evident that manyalternatives, modifications, and variations will be apparent to thoseskilled in the art. Accordingly, it is intended all such alternatives,modifications, and variations as fall within the spirit and broad scopeof the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. The combination of asewing machine having a sewing surface and an attachment for aligning areinforcement member in the hem of a strip of material prior to sewingthe end of the strip of material to form the hem, said attachmentcomprising:a frame having a surface coplanar with the surface of thesewing machine; means mounted on said frame surface for holding a numberof reinforcement members; means mounted on said frame for aligning astrip of material with respect to the sewing machine; means for engagingthe end of said strip of material; means for transporting one of saidmembers from said holding means to a position on said strip of materialand spaced from the end of said strip of material; means for folding theend of the strip of material between said one of said members and saidengaging means around the edge of said member; a shuttle mounted formovement into engagement with the folded end of said strip, said shuttleincluding; means for clamping the folded end of the strip of materialover the top of said member; and means for moving said shuttletransversely toward the sewing machine wherein said folded end isstitched to the strip of material to enclose said member.
 2. Theattachment according to claim 1 wherein said aligning means comprises aguide bar mounted on said frame for movement from a position below saidsurface to a position above said surface to form a guide for one edge ofsaid strip of material.
 3. The attachment according to claim 1 includingmeans mounted on said frame for adjusting the position of said engagingmeans and said clamping means whereby the width of said hem can bevaried.
 4. The attachment according to claim 1 wherein said foldingmeans comprises a folder bar mounted on said frame for movement from aposition below said strip to a position above said strip adjacent tosaid member whereby the end of said strip is folded around the edge ofsaid member.
 5. The attachment according to claim 1 wherein said shuttleincludes a wiper plate for folding the end of said strip over the top ofsaid member.
 6. The attachment according to claim 5 including meansmounted on said frame for adjusting the position of said engaging meansand said shuttle whereby the width of said hem can be varied.
 7. Theattachment according to claim 6 including means on said shuttle forengaging the edge of the end of said strip when said strip is clamped onsaid shuttle.
 8. The attachment according to claim 1 including means onsaid moving means for engaging the edge of the end of said strip whensaid strip is clamped on the shuttle.
 9. A hem folding attachment for ahem forming machine comprising:a frame having a top forming a worksurface; a guide mounted on said frame for aligning a strip of materialon the work surface; a hem stop mounted on said frame for engaging theend of the strip of material; means mounted on said frame for aligning areinforcement member on said strip in a spaced relation to the end ofsaid strip; a folder bar mounted on said frame beneath the strip ofmaterial; means for moving said folder bar into engagement with the endof said strip between said member and said hem stop to fold said endaround the edge of said member; a shuttle mounted for movement intoengagement with the folded end of said strip, said shuttle including awiper plate for folding the end of the strip over said member and aclamp for clamping the folded end of the strip around said member; andmeans for moving said shuttle transversely with respect to said strip tofeed the folded end of said strip into the hem forming machine to securethe folded end to the strip to form the hem.
 10. The attachmentaccording to claim 9 including a magazine mounted on said frame forsupporting a plurality of said members, a blade for transporting saidmembers from said magazine to said strip and a clamp assembly forholding said blade in a fixed position with respect to said strip. 11.The attachment according to claim 10 wherein said strip includes a slotlocated in a spaced relation to the end of said strip and said membercomprises a hanger having a tab positioned to engage said slot when theend of said strip is folded around said hanger whereby said hanger isprevented from moving with respect to said strip.
 12. The attachmentaccording to claim 11 wherein said clamp includes a saw blade positionedto engage the edge of the folded end of said strip to prevent the foldedend of the strip from moving when the strip is moved transversely bysaid shuttle.
 13. A hem forming machine attachment for a sewing machinefor forming a hem on the end of a strip of material with a reinforcementmember enclosed in the hem, said attachment comprising:a table; a guidemounted on said table for aligning a strip of material on the table; ahem stop mounted on said table to engage the end of the strip ofmaterial; a magazine mounted on said table for holding a number ofreinforcement members; a blade for transferring a reinforcement memberfrom said magazine to said strip of material; a clamp mounted on saidtable for holding said blade in engagement with said strip and in aspaced relation to said hem stop; a folder bar mounted on said tablebeneath said strip of material, said folder bar being moveable to aposition above said strip to force the end of the strip between saidblade and said hem stop around said blade; a shuttle mounted on saidtable for movement into engagement with the folded end of said strip;said shuttle including a clamp for engaging the folded end of saidstrip; means for releasing said blade holding clamp from said bladewhereby said blade can be removed from said strip; means for moving saidshuttle, transversely toward the machine for sewing said folded end ofsaid strip to said strip to form the hem.
 14. The attachment accordingto claim 13 wherein said reinforcement member is a hanger.
 15. Theattachment according to claim 13 wherein said reinforcement member is aweight.
 16. The attachment according to claim 13 including means formoving said hem stop and said shuttle with respect to said folder bar toselectively vary the width of said hem.